Jib crane kit



Aug. 26, 1958 w. s. CHAPIN, JR

'JIB CRANE KIT Filed May 20, 1955 Patented Aug. 26, 1958 JIB CRANE KIT William s. Chapin, Jr., Muskegon Heights, Mich., assignor to Manning, Maxwell & Moore, Inc., Muskcgon, Mich., a corporation of New Jersey Application May 20, 1953, Serial No. 356,288

Claims. (Cl. 248-282) The present invention relates to jib crane kits which may be assembled with a locally procured conventional I-beam to form a complete jib crane, and has more particular relation to such a kit of improved construction which is simpler, stronger, more economical to manufacture, and more convenient in assembly and use.

It has been proposed that a construction kit may be provided which is capable of shipment in knock-down form and which may be assembled at the place of use with a locally acquired length of I-beam for forming a complete jib crane. The cost and inconvenience of shipping the beam, the largest and heaviest part of the crane, is thus eliminated. Such a kit has for its principal parts a pair' of brackets adapted to be secured in vertically spaced relation upon a wall, post, or other upright support, a pair of fittings for attachment to either end of an I-beam, and a length of cable or stay. The first of the two fittings is adapted to be journaled in the lower wall bracket to mount the inner end of the beam for horizontal swing, and the second of the fittings is adapted to be secure-d to the other end of the beam as well as to one end of the stay, the

' other end of which is horizontally swiveled in the upper bracket. The beam is thus supported at its inner end by the lower bracket and at its outer end by the stay, yet is adapted for horizontal or jib swing. Such an arrangement is described in U. S. Patent 2,294,998 issued September 8, 1942, in the name of G. A. Mitchell.

It is a general object of the present invention to provide an improved kit of the type described and which requires fewer parts, gives greater strength, and is more easily and quickly assembled.

It is another object of the invention to provide such a kit having fittings which are easily and firmly attached to an I-beam boom.

A further object of the invention is to provide such fittings cooperatively socketed to receive the ends of an I- be'am with a strong mating fit.

Still another object is the provision in such a kit of improved construction for connecting a stay to the outer end of the beam without the necessity of a swivel pin or adjusting turn buckle.

And a further object of the invention is to provide in such a kit new and advantageous means for the swivel attachment of the other end of the stay to a wall bracket, eliminating both the need for a stay thimble and wear on the stay.

Further objects and advantages of the invention will become apparent as the following description proceeds, taken in conjunction with the accompanying drawing, in which:

Figure 1 is a side elevation of a jib crane assembled from a kit embodying the features of the present invention;

Fig. 2 is an enlarged perspective view of one of the Wall brackets employed in the kit;

Fig. 3 is an enlarged perspective view of an inner beam fitting constructed in accordance with the present invention;

Fig. 4 is a perspective view of an outer beam fitting utilized in the present invention;

Fig. 5 is a sectional view taken along line 55 in Fig. 1, further illustrating the outer beam fitting and its attachment to the end of an I-beam; and

Fig. 6 is a perspective view of a flanged bushing employed for pivotally connecting a stay to the upper Wall bracket in accordance with the invention.

Although the improvements of the present invention have been shown and described in some detail with reference to their embodiment in a particular jib crane kit, there is no intention to limit the invention to such details. On the contrary, the intention is to cover all alterations, modifications, and equivalents falling within the spirit and scope of the invention as defined in the appended claims.

Referring now to the drawing, a kit embodying the present invention is there shown assembled with a length of conventional I-beam 10, having upper and lower horizontal flanges 11 and 12 and a vertical web 13, forming the boom of a horizontally swinging jib crane. A rolling trolley (not shown) may advantageously be supported by the lower fiange 12 to carry loads along the length of the beam. The kit includes as its basic elements upper and lower bearing brackets 15 and 16 adapted to be mounted in vertically spaced relation on a wall or column. Inner and outer fittings 18 and 19 are removably secured to the respective ends of the beam, the former being journaled for horizontal swing in the lower bearing bracket 16 and the latter receiving one end of an inclined supporting stay or cable 20 having its other end secured for horizontal swiveling to the upper bearing bracket 15.

In keeping with the invention, the inner and outer fittings 18 and 19 are constructed for matingly receiving respectively the opposite end portions of the I-beam. Each fitting is advantageously made in a single piece and each is formed with a socket 21 and an open-ended slot 22 for the entrance of the upper fiange 11 and the web 13 respectively. As seen in Fig. 3, the socket 21 is defined by an upper plate 23 having its side edges turned down and under to form opposed lower flanges 25 leaving the lengthwise slot 22 opening vertically upward into the socket proper. The upper fiange 11 at one end of an I-beam may thus be inserted lengthwise into the socket 21 with the web 12 riding through the slot 22. The socket is closed at one end by a depending tail plate 27 which constitutes an abutment for engaging the end of the inserted I-beam along both upper and lower flanges 11 and 12 and along the web 13. This tail portion 27 engaging the end of the beam greatly increases the security of the attachment alforded by the upper flange 11 in the fitting socket 21 and in addition provides an end stop for a trolley rolling on the lower flange 12. For additional strength, vertical gussets 28 may be formed between the tail portion 27 and the flanges 25, and reinforcing back ribs 29 may be provided on the rear face of the tail portion.

The upper flange 11 may be secured against vertical play within the socket 21 by a plurality of dog screws 30 threaded through openings in the top plates 23. These may be tightened to bear upon the top of the I-bearn and draw the bottom surface of the socket 21 up against the lower surface of the upper flange 11. Preferably, three such dog screws 30 are provided in each fitting, and made of the headless, socketed Allen type so that they may be tightened into the desired engagement without leaving a projecting head.

While the engagement of the beam ends against the tail portions of the socket and the dog screws prevent both endwise sliding and vertical play of the fittings on an assembled beam, further provision is preferably made for preventing lateral play of the fitting on an assembled beam. Thus, two integral, spaced ears 31 are formed -to project inwardlyfrom thetail portion 27 to define a tapered notch--32 which receivestheweb 130f the-inserted beam, positively centering the beam and wedging the web 13 for support against lateral movement relative-to the fitting. --By this provision it is not-necessary that the edges of the upper fiange=11 engage the side walls of the socket 21, and beams of several different sizes having upper flanges of different widths may be accommodated by the same fittings.

"The upper and lower bearing brackets 15, 16 are advantageously made identical. Thus, each is formed of a single piece, cast body having a flat base 34 with openings' 35 therethrough for receiving fasteners such as bolts 37, and a pair of vertically spaced lugs 38 extending horizontally from the base and reinforced by gussets 39. The lugs 38 have registering openings-40 therethrough'for receiving pintle pins 41which are locked in place by bolts t 42 extending through the pin and a fixed collar 43- on the underside of the lower lug.

The construction described up to this point is substantially identical for both the inner and outer fittings-1'8 and 19. In other respects, their construction differs to 16 swingably supports the inner fitting-18 which'for this purpose has the integral projection 44 mountedon the .pintle pin 41, the upper and lower surfacesof the pro- :jection 44 fitting snugly between the two lugs 38.

The outer fitting .19 has an upwardly andoutwardly angled integral-projection 46 (Figs. 1 and .4) apertured for connection with the lower end of the stay 220.

shown, this projection is reinforced by vertical flanges 47 at either side, and has an elongated opening '48. (Fig. 4) .for receiving a threaded eyebolt 49 towhich thestay 20 -may be secured. The eyebolt 49 includes a shank which is inserted through the opening 48 and held :againstlthe pulling force of the stay by cooperating adjustingand .locking nuts 50 and 51. Preferably, a spacing sleeve 52 is placed on the shank between the projection 46 and. the

'first nut 50, the inner end of the sleeve 52 and-theto-uter mating-face of the projection 46 being preferably arcuately formed. The arcuate surface of the sleeve 521has freely slidable engagement with the concave surface of the projection 46. As the nuts 50, '51 are tightened, the eyebolt 49 rocks within the opening'48 so that itassumes the same inclination of the stay 20. The eyebolt is thus automatically put in direct tension.

For pivotally securing the stay 20 to the upper bracket 15, the upper pintle pin 41 carries a bushing53 journaled on it between the two lugs 38 for horizontal swing. -On the outer surface of this bushing 53 a partiallyuciroumferential, angularly inclined, grooved saddle 54(Fig. 6) is formed forreceiving an upper bight of the stayy20. The grooved saddle 54 on the bushing securely'holdsathe upper end of the stay in its proper generally downwardly inclined orientation and, since-as the jib is swung horizontally the bushing 53 itself rotates on the pintle pin 41, there is no wear on the stay and no necessity' for using a thirnble in its upper bight. The stay 20 thus extends from. the upper bearingbracket 15 to the eye of the eyebolt 49, being formed into bights at'either endby-suitable clamps 55. If desired, a metal thirnble 56 maybe utilized in the lower bightv to prevent a sharp-bend oftthe stay in passing through the eyebolt. The clamps 55 themselves permit considerable adjustment of the length of the stay 20 and the amount of support itatfords for the outer end of the beam 10, but final length and tension adjustment can be made by means of the adjustment nut 50 on the shank of the eyebolt 49. The whole jib may be swung freely in a horizontal plane, the boom itself swinging With the journaled projection 44 on the inner fitting 18, and the stay 20 swinging on the, journaled single-piece fittings socketed to freely receive the flanged 4f. bushing 53 to provide constant support of the outer end of the-boom.

From the foregoing, it=will be seen that the present crane kit provides for the simple and strong components which may be assembled with an I-beam in an instant to form a complete jib crane. The parts may be manufactured conveniently, as by casting, and no separate clamping members are necessary for the beam fitttings by virtue of their slotted socket construction for mating -with an I-beam. Further, the stay connection is. particularly simplified and sturdy, at the upper end by the saddled bushing and at the lower end by a single eyebolt adjustably held through the angled projection of the outer fitting.

I claim as my. invention:

1. In a kit for assembly with a length of I-beam and a pair of bearing brackets adapted to be mounted at vertically spaced points on a vertical surface to form a jib crane, that improvement of, first and second one-piece cast fittings adapted to be secured to the respective ends of the I-beam, each of said fittings having an integrally formed socket for receiving the upper flange of the 'I-beam and a slot opening into the socket for receiving the Webof the beam, each fitting having a tailpiece at the rear of its socket to'form an abutment'for the end of the beam, a pair of spaced ears on each said tailpiece defining a tapered notch for wedgingly receiving and centering the web of the beam, means for journaling said first fitting on'the lower bracket, and a stay connected between-the upper bracket and said second fitting.

'2. Ida kit for assembly'with a length of conventional I-beam to form a jib crane, and including a pair of'bearing-brackets adapted to be mounted at vertically spaced points'on a vertical surface and each having a pintle pin therein, the improvement comprising first and second upper'portions of respective ends of an I'-beam, each fitting'having a tail piece arranged to extend down along the adjacent end of the I-beam and having a tapered notch in its inner face for reception of the beams web to I thereby'fix the lateral location of the fitting upon Wedging of the web in such notch, dog screws threaded in the upper portions of said fittings for drawing the undersides -of'their socketed portions snugly up against theunderfaces of the beams top flange, an'integral projection on said first fitting adapted for jonrnaling on thelower pintle -pin,.and a stay adaptedto extend diagonally'downward wall; a vertical pintle pin secured in each of said'brackets;

first and second single-piece fittings socketed to receive the upper flange of the respective ends of an I-beam; each fitting including an upright abutment for'engaging the respective end portions of the beam; an integral endwise projection on said firstfitting journaled on the 'lower pintle pin for horizontal swing; an upwardly inclined projection on said second fitting having an opening therethrough; a threaded eyebolt having its shank inserted through said opening and secured by an adjusting nut; a bushing journaled on the upper pintle'pin and having a partially circumferential, upwardly inclined, grooved saddle On=its outer surface; and a flexible stay having a bight at one end lying-in said saddle and a bight at-the other end passing through the eye of said'eyebolt to provide support for the outer end of the beam.

4. In a jib crane including a length of conventional I-beam, a pair of bearing brackets adapted to be mounted at vertically spaced points on a wall with a vertical pintle pin in each of said bracketsythe improvement comprising first and second single-piece 'fittings removably secured tothemespective ends of said I-beam, an apertured integral projection on said first fitting which is pivotally received on the lower pintle pin, a stay having one of its ends journaled on the upper pintle pin, an eyebolt having the other end of the said satay secured through its eye, said second fitting having an integral, upwardly extending, arcuate projection inclined angularly outwardly toward the free end of said l-beam and presenting a concave surface on the side thereof which is remote from said stay, said projection having an elongated opening extending lengthwise thereof, said eyebolt having a threaded end opposite its eye and extending through said opening, a sleeve on the end of said eyebolt and having a convex end surface matingly engaging said concave surface, and a nut threaded on said eyebolt pressing against said sleeve for tightening said stay, relative sliding between said convex and concave surfaces in response to such tightening causing the eyebolt automatically to swing within said opening and to aline with said stay so that the eyebolt is free of bending stresses.

5. In a jib crane having upper and lower bearing brackets adapted for mounting in vertically spaced relation, vertical pintle pins in the brackets, a length of conventional I-beam, fittings attached to opposite ends of said I-beam and journaled respectively on the lower pintle pin and receiving the lower end of a flexible stay which extends in an upwardly inclined direction toward said upper bracket, that improvement which comprises a bushing journaled on the upper pintle pin and formed with an integral, semi-peripheral, upwardly inclined grooved saddle on its outer surface disposed obliquely to the vertical axis of the bushing, and means forming a bight in the stay which lies around said bushing and in said saddle, so that the stay is not sharply bent and has no rubbing contact as the I-beam is swung horizontally about the lower pintle pin.

References Cited in the file of this patent UNITED STATES PATENTS 469,048 Renehan Feb. 16 ,1892 483,071 Lucas Sept. 20, 1892 925,968 Webb June 22, 1909 1,578,634 Borgmann Mar. 30, 1926 2,255,531 Pittman et al. Sept. 9, 1941 2,294,998 Mitchell Sept. 8, 1942 2,564,935 Templeton Aug. 21, 1951 2,640,506 Consoletti June 2, 1953 

